* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    height: 100vh;
    background: rgb(255, 94, 249);
    background: linear-gradient(144deg, rgba(255, 94, 249, 1) 19%, rgba(104, 185, 251, 1) 86%);
    color: white;
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
}

#logoBox{
    position: relative;
    left: -600px;
    top: -410px;
}

#logo {
    position: absolute;
    left: 200px;
    top: 150px;
}

#title {
    position: absolute;
    font-family: 楷体, 微软雅黑, serif;
    display: inline-block;
    width: 420px;
    height: 90px;
    text-align: justify;
    left: 230px;
    top: 260px;
    font-size: 45px;
    content:'';
}

/* 表单属性 */
.container {
    position: relative;
    background-color: rgba(0, 0, 0, 0.4);
    padding: 20px 40px;
    border-radius: 5px;
    left: 300px;
    /*禁止文字被选中*/
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/*装管理员/教师/学生的盒子*/
#identity {
    width: 100%;
    height: 70px;
    align-items: center;
    justify-items: center;
    display: inline-block;
    border-bottom: 3px solid rgb(110, 154, 247);
    animation: conversion 4s linear infinite;
}

@keyframes conversion {
    0% {
        border-bottom: 3px solid rgb(104, 185, 251);
    }

    33% {
        border-bottom: 3px solid rgb(255, 150, 116);
    }

    66% {
        border-bottom: 3px solid rgb(255, 94, 249);
    }

    100% {
        border-bottom: 3px solid rgb(104, 185, 251);
    }
}

/*管理员/教师/学生  的三个标题*/
#identity > label {
    float: left;
    margin-top: 20px;
    width: 33%;
    height: 50%;
    font-size: 22px;
    line-height: 35px;
    text-align: center;
    color: #d4d4d4;
    border-right: 3px solid #ffffff;
    transition: all 0.1s cubic-bezier(0.7, 0.5, 0.3, 1);
}

#identity > label:last-of-type {
    border-right: 0 solid #e91e63;
}

/*管理员/教师/学生  的三个标题*/
#identity > label:hover {
    color: rgb(48, 240, 249);
    font-size: 24px;
}

/* 表单中标题属性 */
.container h1 {
    text-align: center;
    margin-top: 20px;
    margin-bottom: 30px;
    font-family: '楷体', '微软雅黑';
}

/* 鼠标经过时字体颜色改变 */
.container h1:hover {
    background-image: linear-gradient(90deg, #673ab7, #e91e63);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-image: linear-gradient(90deg,
    rgb(255, 167, 69),
    rgb(254, 134, 159),
    rgb(239, 122, 200),
    rgb(160, 131, 237),
    rgb(67, 174, 255),
    rgb(160, 131, 237),
    rgb(239, 122, 200),
    rgb(254, 134, 159),
    rgb(255, 167, 69));
    background-size: 200%;
    animation: streamer 3s linear infinite;
}

/* 字体颜色变化的动画 */
@keyframes streamer {
    0% {
        background-position: 200%;
    }

    100% {
        background-position: 0%;
    }
}

/* 按钮的属性 */
.btn {
    cursor: pointer;
    width: 100%;
    background-color: lightblue;
    padding: 15px;
    border: 0;
    font-size: 16px;
    font-family: 微软雅黑, serif;
}

/* 点击按钮时的属性 */
.btn:focus {
    outline: 0;
}

/* 点击按钮时的效果,缩小0.98 */
.btn:active {
    transform: scale(0.98);
}

.text {
    margin-top: 30px;
}

/* 输入框所在容器的类 */
.form-control {
    width: 300px;
    margin: 20px 0 40px;
    position: relative;
}

.form-control input {
    width: 100%;
    height: 60px;
    background-color: transparent;
    border: 0;
    border-bottom: 2px solid white;
    display: block;
    padding: 5px 0;
    font-size: 18px;
    color: white;
}

/* 获取焦点时下边框变为蓝色 */
.form-control input:focus {
    outline: 0;
    border-bottom-color: lightblue;
}

/*当输入框中有文字时，下边框还是蓝色  valid：检测input有没有填*/
.form-control input:valid {
    border-bottom-color: lightblue;
}

/* Email与password的属性 */
.form-control label {
    position: absolute;
    left: 0;
    top: 15px;
}

/* Email与password的动画效果 */
.form-control label span {
    display: inline-block;
    font-size: 18px;
    transform: translateY(-30px);
}

/* +选择器：选择除了自己之外的其它兄弟元素 */
.form-control input:focus + label span,
.form-control input:valid + label span {
    transform: translateY(-30px);
    color: lightblue;
}